The instant invention relates to watch case assemblies and the like which heretofore have been made from various metals such as gold, silver or stainless steel. Gold watch cases have always been among the most expensive cases available but despite their cost they have always been extremely popular as a result of their rich, attractive appearance. One of the unfortunate disadvantages, however, heretofore encountered with watch case assemblies constructed entirely of gold is that the back portion of the case can some times create an adverse reaction with the skin of the wearer. While this is not a problem for the majority of people, nonetheless there are a substantial number of people who cannot wear gold watches as a result of their extremely sensitive skin. A further disadvantage heretofore experienced with gold watch cases is that after a period of time the back portion of the case which contacts the wearer's skin can become pitted or corroded from perspiration, causing the gold to loose its rich attractive appearance. The instant invention effectively eliminates these and other disadvantages by providing a bi-metallic watch case assembly having a gold main casing and a stainless steel back portion. While it is not necessarily new to combine a stainless steel watch back with a gold or gold plated casing, the assembly of the instant invention effects this combination in a novel way wherein the stainless steel back of the watch is completely hidden from view when the watch is positioned on the wrist of a wearer. Previously known assemblies have generally effected the attachment of the stainless steel watch back by providing a back having a peripheral rim or ridge which is receivable in engagement within the side walls of the casing and as a result tends to raise the casing somewhat from the wrist of the wearer. The main disadvantage here is that the stainless steel back may be visible to an observer since it is not always concealed from view. While this may be of little significance with less expensive watches, it is of far greater importance with the more expensive gold watches. The assembly of the instant invention provides a novel and effective means for attaching a stainless steel back to a gold watch wherein the stainless steel insert portion is completely hidden from view when the watch is being worn.
In addition to providing an effective means of attaching a stainless steel back to a gold main casing, the assembly of the instant invention provides a novel means for positioning the movement portion of a watch within the main casing using a gold or stainless steel movement retaining ring. While it is not broadly new to position the movement portion of the watch within the main casing in this general manner, the movement retaining ring, disclosed in the instant invention effects a dual purpose by both positioning the movement within the main casing and also acting as a portion of the assembly used to secure the rear wall to the main casing.